Overall Info

To accomplish this task they are equipped with a few specialties:
- They auto-lock incoming missiles meaning the pilot just has to launch the Defender I
- Powerfull jet engines that boost their speed far beyond of what other missiles are capable of.
- Every Missile/Rocket launcher can be loaded with Defender missiles.

Due to their design, defenders cannot be launched as an offensive weapon to attack other ships, neither can they be used to defend other friendly ships from incoming hostile missiles.

Fitting more than one launcher with Defender Is is highly questionable because of their weak coordination.
Every Defender missile launched will target the same incoming missile until the incoming missile is destroyed, meaning 5 Defenders launched at the same time will kill only one incoming missile.

Defender missiles are a way of decreasing incoming damage. However, they are barely being used in pvp due to the nature of engagements in Eve. By the time you might want to switch from damage dealing missiles to defenders you're already in big trouble.

It has to be noted that some missiles may require more than one defender missile hit before being destroyed.
Also, because of their self-contained locking mechanism, defender missiles will not be affected by any jamming system. Thus, a ship which is target jammed will still be able to use effectively its defender missile system.

One final word, defender missiles are only effective against other missiles and are totally useless against laser or projectile attacks.

Most of the community regards(without fear of being contraddicted and for a reason) defender missiles useless.